There has been known a laser printer capable of forming a color image. Such a laser printer includes a main frame having a pair of side walls spaced apart in a horizontal direction, and each of the side walls includes a resin frame and a metal frame.
The laser printer also includes a plurality of image forming units disposed between the side walls and a belt unit disposed beneath the image forming units. Each image forming unit includes a photosensitive drum for bearing a toner image. The belt unit is mainly made of resin and supported to the resin frames of the side walls. The belt unit includes a belt frame, a pair of belt support rollers supported to the belt frame, and an endless conveying belt wrapped around the pair of belt support rollers.
A drive motor is disposed on the resin frame, and a gear is attached to an output shaft of the drive motor. Another gear is attached to one of the belt support rollers and is in meshing engagement with the gear attached to the output shaft of the drive motor.
With this configuration, during image forming operations, driving force generated by the drive motor is transmitted to the belt support roller to rotate the same. Rotation of the belt support roller rotates the conveying belt to covey a sheet of recording paper, and the toner image formed on each photosensitive drum is transferred onto the recording paper on the conveying belt.